49 lines
1.7 KiB
Haskell
49 lines
1.7 KiB
Haskell
import Data.List
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import Data.List.Split
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import Data.Maybe
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import qualified Data.Text as T
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main :: IO ()
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main = do
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let toDigit = T.unpack . T.replace (T.pack "10") (T.pack ":") . T.pack
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input <- map (map toDigit . lines) . splitOn "\n\n" <$> readFile "input"
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print $
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sum $ zipWith (*) [1 ..] $ map (fromEnum . isOrdered 0) input
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let divider = ["[[6]]", "[[2]]"]
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let sorted = sortBy mySort (divider ++ concat input)
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print $ product $ map (+ 1) $ mapMaybe (`elemIndex` sorted) divider
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isOrdered :: Int -> [String] -> Bool
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isOrdered n [l:ls, r:rs]
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| n < 0 && l == ',' = False
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| n > 0 && r == ',' = True
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| l == r = isOrdered n [ls, rs]
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| l == ']' = (r /= ',') || isOrdered (succ n) [ls, r : rs]
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| r == ']' = l == ',' && isOrdered (pred n) [l : ls, rs]
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| l == '[' = r /= ']' && isOrdered (pred n) [ls, r : rs]
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| r == '[' = l == ']' || isOrdered (succ n) [l : ls, rs]
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| l > r = False
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| l < r = True
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| otherwise = False
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isOrdered _ [[], _] = True
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isOrdered _ [_, []] = False
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isOrdered _ _ = True
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addBrackets :: [String] -> [String] -> [String]
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addBrackets [accl,accr] [l:ls,r:rs]
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| l == r = addBrackets [l:accl,r:accr] [ls,rs]
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| l `elem` ['0'..':'] && r `elem` ['0' .. ':'] = addBrackets [l:accl,r:accr] [ls,rs]
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| l == '[' = addBrackets [l:accl,l:accr] [ls,r:rs]
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| r == '[' = addBrackets [r:accl,r:accr] [l:ls,rs]
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| l == ']' = addBrackets [accl,r:accr] [l:ls,rs]
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| r == ']' = addBrackets [l:accl,accr] [ls,r:rs]
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addBrackets [accl,accr] ["",rs]= map reverse [accl,reverse rs ++ accr]
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addBrackets [accl,accr] [ls,""] = map reverse [reverse ls ++ accl,accr]
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addBrackets _ acc = map reverse acc
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mySort :: String -> String -> Ordering
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mySort x y =
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if isOrdered 0 (addBrackets ["",""] [x, y])
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then LT
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else GT
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